Automatic electric switch.



E. W. DAVIS.

AUTOMATIC ELBGTRIG SWITCH. APPLICATION TILED 001'. 22, 1910.

1,004,383. Patented Sept. 26, 1911.

19- 2 my. a i

PVITNESSES: INVEZVTOR.

. creasing ERNEST W. DAVIS, OF CHICAGO, ILLINOIS.

AUTOMATIC ELECTRIC SWITCH.

7 Specification of Letters Patent.

' Patented Sept. 26, 1911.

'Application filed October 22, 1910. Serial No. 588,472.

To all whom it may concern:

Be it known that I, ERNEST W. DAVIS, a

citizen of the United States, and a resident of the city of Chicago, inthe county of Cook and State of Illinois, have invented a new andImproved Automatic Electric Switch.

This invention relates to devices for automatically opening and closingelectrical circuits,such as are used for operating flashlarly toflashing devices in which the operating power is obtained from a magnetor solenoid instead of a motor.

Solenoid-operated flashers as heretofore constructed have provedunsuitable for operating heavy switches, such as are required forcurrents of high amperage. In flashers of this class the movement of thecore is retarded by various means, such as a revolving fan, a dash pot,a metallic disk rotating in a magnetic field, etc. As usuallyconstructed the movement of the core from one extreme position to theother is retarded by the fan, dash pot, or other device, and the changein the circuit is produced by a slight amount of movement at the end ofeach reciprocating movement of the core. The defeet oflsuch aconstruction lies in the fact that a large part of the energy producedby each stroke of the core is used to overcome the retarding means andthe little energy remaining is insuflicient to make forcible connectionsat the switch contacts. Obviously, this defect may be overcome by'inthesize of the solenoid, but when thus constructed the device would be nocheaper to produce than an eflicient motor driven flasher and wouldconsume several times the amount of current in operation.

The object of this invention is to overcome the above namedobjectionsand to produce an automatic electric switch which will op crate largecontacts and make more forcible connections than the previouslydescribed flashers, without increasing the size of the solenoid. Iattain this object by usin a flywheel or other inertia member, in.p aceof the fan, dash pot, etc., used in other flashers. Ihave demonstratedby practical tests that the retarding effect of a fly wheel, due toovercoming its inertia, is sufficient to produce intervals of therequired time. I have also demonstrated that the power which is impartedto the fly wheelis not entirely dissipated as it is in a'fan or dashpot, but may electric signs, and relates more partlcu-l -ments of thecore reciprocating movement of the rack 3, the

be easily regained, as the revolving fly wheel has considerable energydue to its momentum. In my invention this energy, due to the momentum ofthe fly wheel, is used to make forcible connections at the switchcontacts, which forcible connections are very necessary for. operatingwith heavy currents.

In order to make the invention more clearly understood reference is madeto the accompanying drawing, in which:

Figure 1 is a front elevation. Fig. 2 is a circuit diagram of theapparatus shown in Fig. 1. Fig. 3 is a circuit diagram with duplicatesolenoids.

The solenoid 1, Fig. 1, is provided with a paramagnetic core 2, whichmoves verti cally in said solenoid. A rack 3, is connected to said coreand is provided with arms 4 and 5, which engage with an insulating'roller 7, and. thereby operate the switch 8. The rack 3, engages with apinion 9, which operates a train of gears 10 and 11, and thereby impartsrapid rotation toa fly wheel 12, which by its inertia, retards the move-2. At theend of each fly wheel 12, by virtue of its momentum producesforcible contact between the switch 8,

and the contacts 15 and 18.

In operationg'the current entering at 13 passes through the lamp 14,switch 8, con tact 15, and back to the line 16.- The currentv is alsoshunted at 17 and flows through the solenoid 1, to the switch 8. Thesolenoid 1, being thus energized, raises the core 2, and brings theswitch 8, in connection with the contact 18. With the switch 8 in thisposition, the currententering at 13, passes to the contact 18, throughthe switch 8, and lamp 19, back to the line 16. The solenoid 1, is thenshort circuited through the switch 8, and contact 18, and is denergized.This allows the core 2, to fall by the action of gravity, but beforedoing so the fly wheel 12, by virtue of its momentum, ,jams the switch 8in forcible-connection with the contact 18. When the core 2, falls toits lowosition the switch is returned to its automatic, electricswitches have been used which were operated by solenoid and in whichvarious retarding means were employed. I therefore do not claim such acombination broadly. What I claim as being new and useful and that whichI desire tends to continue the motion of said core.

to secure by Letters Patent is the use of a retarding meansin which theimparted energy may be regained and made to assist in operating theswitch.

In devices of this class as previously constructed the efficiency hasbeen low, as only a fraction of the total energy of the solenoid isutilized in actual operation of the contacts, while in the improveddevice the mechanical efiiciency is theoretically perfect, as the totalamount of kinetic energy produced in the solenoid is utilized,theoretically, in operating the switch.

I claim:

1. In combination, an electric switch; a transforming means, capable oftransforming electrical energy into kinetic energy; means whereby saidswitch is operated by said kinetic energ an inertia member arranged toretard the motion produced by said kinetic energy, said inertia memberbemg so arranged that the energy imparted thereto tends to continue theduced by said kinetic energy.

2. In combination, an electric switch; an electric solenoid, providedwith a movable, paramagnetic core; means whereby said motlon pro- .core;a rotatable inertia member, said core and capable of retardlngthemocore; a rotatable inertia member driven by said core and capable ofretarding the motion thereof; sa1d incrtla member being so arranged thatthe energ imparted thereto 3. In combination, an electric switch; anelectric solenoid: provided with a movable paramagnetic core; meanswhereby said switch is operated by the movement of said driven by tionthereof, said inertia member and said switch operating means, being soarranged that the energy imparted to said inertia member is transmittedthrough said switch operating means and thereby makes forcibleconnections at the contacts of said switch. 4. In combination, anelectric switch; an electric solenoid provided with a movableparamagnetic core; means whereby said switch is operated by-the movementof said core; a rack connected with said core; a pinion in mesh withsaid rack; a train of gears operated by said pinion; and a rota tableinertia wheel operated by said gears. In testimony whereof I afliX mysignature in the presence of two witnesses.

' ERNEST W. DAVIS. Witnesses:

C. K. CHAMBERLAIN, A. S. PHILLIPS.

